Metal deformation

This morning I hard soldered a 26 gauge fine silver bezel to a sheet
of 20 gauge sterling silver. After test fitting the stone, I noticed
the sheet had bowed upward from the middle and the stone would not
lay straight. What causes this? Did I get the metal too hot? I let
the metal air cool and did not quench it. Thanks guys.

What causes this? Did I get the metal too hot? 

Could be, but I would guess that pieces were not annealed before
soldering, or some other tension was present. To prevent it, simply
anneal, pickle, and than solder. And do not use any binding wire.
Make bottom a bit larger and trim after soldering. It means that
bezel sits on top of plate. If bottom fit tightly inside the bezel,
it could be the cause for buckling as well.

Leonid Surpin

This morning I hard soldered a 26 gauge fine silver bezel to a
sheet of 20 gauge sterling silver. After test fitting the stone, I
noticed the sheet had bowed upward from the middle and the stone
would not lay straight. What causes this? Did I get the metal too
hot? I let the metal air cool and did not quench it. Thanks guys. 

Funny you should mention this, something like this happened to me
also.

Did you roll the sheet yourself, or did you buy the sheet?

I was experimenting with really thin gauges of sterling, and did it
ever buckle and bow… quite artistically really, so it was a nice
surprise.

The metal was fixed, and not allowed to expand, so when heat was
applied the metal bowed because it had nowhere else to go.

Regards Charles A.

My thoughts: Sounds like the silver wasn’t fully annealed before
soldering. Is it were dead soft, buckling shouldn’t have occurred.

Jeff Herman

This sheet was bought from rio. Anything I can do with the metal to
prevent it from buckling?

What causes this? Did I get the metal too hot? 

Leonids post today answers your basic question, ie, the metal wasn’t
properly annealed before you soldered the two together.

I’d add one note though. Especially on larger items, and especially
when working with metals that, unlike silver, may not be such
excellent conductors of heat, it’s sometimes problematic to assemble
things with perfectly flat sheet, as it can sometimes warp,
particularly if other things are already soldered to it. One means to
control this is to very gently planish the sheet metal before
soldering to it. You work mostly in the center, and with softer
metals, you can even use something soft like a rawhide mallet. The
idea is that by very faintly stretching the center of the sheet, you
are producing a very slight domed shape, rather than fully flat. It
does not need to be much. Even barely perceptable. But with that dome
shape, if the metal now wishes to deform or warp, what tends to
happen is that the dome either increases in height or decreases, but
the sheet basically stays in much the same plane. On cooling,
whatever thermal expansion changed the shape, reverses itself, so you
maintain the shape you started with. Way back “when”, doing things
like boxes or similar constructions, I’d want a bottom to the box
that sat flat on a surface, without rocking. Very slightly doming the
metal before assembly meant that you could be sure you’d not end up
with a container who’s bottom bulged out and didn’t sit right.
Working on your cabs, you can do the reverse, insuring that the
bottom, if it no longer is perfectly flat, at least bulges down, not
up, into the bezel, so the stone still fits all the way down.

And one other note. You did say you’re working with sterling (very
soft metal, after all) with decent thickness. So rather than
agonizing over the fact that the bottom warped, why not just fix it?
Put the bezel on a nice flat steel surface, and with perhaps even
just a piece of wood dowel as a punch, or if you need, a flat ended
steel punch (perhaps the back end of a dapping punch, or whatever
else you might have around), “hammer” the center back down. It
shouldn’t be much trouble to flatten that back surface enough so you
no longer hve a problem fitting the stone… You can also do this
effectively from the back. Hold a suitable steel rod (or anything
else the right shape), with a nice flat end, facing upwards, if a
vise. Now support the bezel’s base from the inside, on that surface,
which we’ll now be calling a “stake”… You can now gently planish
the back, working mostly the outer edges. The hammer will drive the
sides down, the stake supports the middle, and you end up with a
flat surface again…

Peter

1 Like

Thanks to everyone for your input.

Best,
Chris Young

This sheet was bought from rio. Anything I can do with the metal
to prevent it from buckling? 

You didn’t do anything to it.

Chances are you didn’t give the piece room to move, similar to what
I did.

The next time for me, I’m going to leave the metal some room to
move.

Regards Charles A.

Charles A.:

This is an old thread I know, but I re-read it before cleaning my in
box. I had a thought-if one were to cut out a shape out of the sheet
that fits behind the stone? Would the metal then have someplace to
move a bit? Is it easiest to pierce while there is not a bezel to
work around? Some who use cabs of translucent materials do the
piercing as a matter of course-usually a silhouette of an animal or
something. I just haven’t asked them ‘when’ they do the piercing. I
don’t yet do a lot of soldering or bezel making, but I do a lot of
thinking about things! With a purposed piercing, you don’t have just
a hole to help remove the cab during fitting… I love Orchid
because it helps me to avoid problems and see solutions I might not
otherwise consider.

Regards,
Eileen
Snow Goose Designs

Is it easiest to pierce while there is not a bezel to work around? 

Yes, but it is not a good idea, in my experience.

I often pierce inside bezels, always after soldering, so I can
locate the piercings exactly where I want, relative to the bezel.

As for getting the stone out-- drilling a hole is a last resort.
Just put a piece of dental floss across the bezel, so you can use
that to pull out the stone. When you are SURE everything is right, of
course, remove the dental floss and close the bezel.

Noel